Machine for extracting precious metals



Nov. 4, 1941- E. e. THOMPSON MACHINE FOR EXTRACTING PRECIOUS METALS Filed Feb: 2, 1939 2 Sheets-Sheet 1 Eddie Thampson INVENTOR.

VIHI" vII ATTORNEY.

Nov. 4, 1941. E. ca. THOMPSON 2,251,574

MACHINE FOR EXTRACTING PRECIOUS METALS I Filed Feb. 2, 19:59 2 Sheets-Sheet 2 & a:

Eddie C7. Timmpson INVENTOR.

ATTORNEY.

Patented Nov. 4, 1941 MACHINE FOR EXTRACTING PRECIOUS METALS osrlcs Eddie G. Thompson, Minot, N. Dak. Application February 2, 1939, Serial No. 254,192

8 Claims.

This invention relates to a machine for extracting gold and other precious metals.

More specifically, the invention relates .to machines of thetype in which precious metals are extracted from their ores, by a mercury amalgamation process.

An object of the present invention is to, provide a simple compact machine containing a complete amalgamation system, which may be conveniently moved from place to place as desired.

Another object is the provision of an amalgamation machine in which the feed rate of the material, the water consistency thereof, and the rate of flow through the amalgamation process are at all times under the control of the operator and may be quickly adjusted.

Another object is to provide an amalgamation process machine having improved means for producing contact between the mercury and the gold bearing material, and in which a largearea of mercury contact can be provided with a minimum quantity of mercury. a

Another object is to provide an amalgamation process machine in which the amalgamation surfaces may be easily removed for cleaning, and a on the line ll of Fig. 3, showing one illustrative form'which'the machine may take.

Fig. 2 is an end view of the illustrative machine mechanism.

Fig. 3 is a transverse sectional view taken substantially along the line 33 of Fig. 1.

Fig. 4 is a longitudinal sectional view on an containing gold or other precious metals, such as placer sands, earth or clay, or stone or stony matter crushed or powdered, or any other precious metal-bearing material in a finely divided state.

Near the bottom of the hopper; l2 are a pair 30 and connecting cross rods SI.

of oppositely rotating rolls l3, each equipped with peripherally spaced longitudinal ribs. Each of the rolls is journalled at its ends in the hopper and the frame ll. Oneof the rolls carries a pulley I l, which is driven my a motor I5 or other source of motivepower through any suitable means such as the appropriate pulley and belt arrangement shown, and serves to drive the other roll through the intermeshinggears [6.

The material from the hopper is directed onto the rolls by an arrangement of guides adjacent the bottom of the hopper, including a central spreader i l of inverted V-shape, distributing material towards the two rolls. A pair of outer plates l8 are hingedat their tops and rockable to.

regulate the size of the opening above each roll and thus control therate of delivery of material from the hopper. Control of the plates IB is attained by supporting their lower ends on cams l9 mounted on rock shafts 20, which shafts carry levers 2| upon their ends outside of the hopper and are retainable in desired position by means such as the thumb screws 22.

Material from the rolls l3 falls upon a series of guide plates 23, disposed crosswise of the rolls, and inclined to receive the material from the rolls and direct it onto the amalgamating trays later to be described. Each of the guide plates 23 is hung from a pivot rod 24 and may be swung into desired position by means of a bar 25 connecting all of the plates and adjustably fixed at one end by appropriate means such as a bolt and slot connection 26 to maintain the plates in position.-

As the material passes over the inclined plates 23, it receives water from a series of perforated pipes 21, one pipe being arranged adjacent each plate to spray water over the surface thereof. Appropriate supply means 28 leads water to the pipes 21, and a valve 29 may be used to control the amount of water delivered from each of the pipesZ'I.

;As the mixture of water and sands flows from the plates 23,, it falls upon the series of amalgamating trays arranged therebeneath. Several series of these trays are provided, all being parallel and spaced from each other and inclined in overlapping arrangement. One series of trays is arranged beneath each of the plates 23, to receive material therefrom. Since each series of trays is identical, only one will be described as typical.

'Ihe several trays of each series are hung upon a rack-consisting of a pair of side bars The trays 32 are removably suspended by and between successive cross rods 3| in overlapping relation so that together they form channels extending lengthwise of the inclined rack. Each tray is formed of a piece of sheet metal bent to provide a bottom 33 and upright sides 34. Near the lower end of each tray the bottom 33 is bent upwardly to provide a trough-forming shoulder, and thereafter again bent at 35 to form a lip adapted to overlap the next tray of the series, and also to project over one of the supporting rods 3|. At its upper end the bottom portion 33 is also bent downwardly to provide a hook for engagement with the next higher supporting rod 3|.

Although each tray 32 may be made of metal of any kind desired, the trough portion at least is preferably provided with a surface which will readily amalgamate with mercury and for this purpose the trough in this instance is provided with a copper lining 36. Each trough contains a batch of mercury 31 and a rod or bar 33 extending across the tray. The rod serves to retain the mercury against washing away under the action of the metal-bearing materials passing thereover, and also serves to present an increased amalgamating surface to such materials, the rod being floated on the mercury and being formed of copper or other good amalgamating material for that purpose.

As the mixture of gold bearing sands and water flows through 'each tray 32, it encounters the surface of the mercury bath 31, and also encounters the surfaces of the copper rod 38 and the copper lining 36 of the trough, which surfaces are kept constantly coated with mercury by the movement induced by the flowing mass. The mercury amalgamates with the precious metals in the sands, and retains the metal amalgam as a deposit upon the copper surfaces. The copper rod 38 floating upon the mercury bath is constantly rotated, either by the moving mass of sand material, or by the Weight of accumulated metallic amalgam upon its surface, thus constantly presenting surfaces newly coated with mercury to the passing material, thereby providing an area of mercury contact far beyond that possible with a bath of mercury alone. The sand and water mixture, in passing through each tray, sweeps over the trough therein and over the lip 35 thereof onto the next lower tray in the series. During its passage over each succeeding tray, the material is again stirred up so that other portions of the material will be presented to the mercury therein. If desired, the copper rod 38 or the copper lining 36, or both, may be electrically charged to increase the activity of the mercury.

In order to control the rate of descent of the sand and water mixture over the amalgamating trays, the racks are swingably mounted to permit changing of their inclination. For this purpose each of the side arms 30 is pivoted at its upper end to the frame H, as indicated at 39 in the drawings. At their lower ends, the bars 30 are pivoted to common side bars 40, supported upon a rod 4! in the side frame II. By varying the vertical position of the rod 4| the inclination of the racks carrying the amalgamating trays may be easily varied.

When the rod 38 and copper lining 36 of the troughs have become sufficiently coated with metallic amalgam to make cleaning advisable, this may readily be accomplished by removal of the trays 32, since the trays are merely loosely placed in the supporting racks. The rods 38 and troughs 36 may then be cleaned to remove the precious metal amalgam therein, the troughs recharged with mercury, and the trays replaced in position.

With the machine described, it is possible to remove the trays 32 for cleaning without interrupting the operation of the machine. To accomplish this, the interior of the hopper l2 may be temporarily divided at any point or points desired by any appropriate means, such as a removable plate or partition 42. For instance, with such a partition inserted in the mid-position indicated in Fig. 1, material continued to be supplied to the left hand portion of the hopper will be directed only into those trays supported in the three left hand racks 30, while the trays from the other racks are removed for cleaning. Likewise, after replacing the cleaned trays in the right hand racks, the metal bearing materials may be directed onto them through and from the right end of the hopper, while the trays from the first mentioned racks are being removed, cleaned, and replaced.

Various changes may be made in the embodiment of the invention hereinabove specifically described without departing from or sacrificing the advantages of the invention as defined in the appended claims.

I claim:

1. In a machine of the character described the combination of a plurality of separate inclined channels each having a succession of mercury retaining recesses therein, a hopper above said channels, and means for directing metal bearing materials from said hopper to each of said channels to effect passage of said material over said recesses and into contact with the mercury contained therein, said means comprising at least one feed roller underlying said hopper and extending transversely of said channels and overlying a plurality of said channels so that material fed by different longitudinal sections of said feed roller is delivered into different ones of said channels, said means comprising plates, one located above each channel said plates extending transversely with respect to said feed roller, the position and inclination of the plates being such as to feed material into the upper portions of the respective channels, and means for varying the inclination of said plates.

2. In a machine of the character described the combination of a plurality of separate inclined channels each having a succession of mercury retaining recesses therein, a hopper above said channels, and means fordirecting metal bearing materials from said hopper to each of said channels to effect passage of said material over said recesses and into contact with the mercury contained therein, said means comprising at least one feed roller underlying said hopper and extending transversely of said channels and overlying a plurality of said channels so that material fed by different longitudinal sections of said feed roller is delivered intodifferent ones of said channels, said means comprising plates one located above each channel said plates extending transversely with respect to said feed roller, the position and inclination of the plates being such as to feed material into the upper portions of the respective channels, and a common means for simultaneously varying the inclination of said plates.

3. In a machine of the character described the combination of a plurality of separate inclined channels each having a succession of mercury retaining recesses therein, a hopper above said channels, and means for directing metal bearing materials from said hopper to each of said channels to effect passage of said material over said recesses and into contact with the mercury contained therein, said means comprising at least one feed roller underlying said hopper and extending transversely of said channels and overlying a plurality of said channels so that material fed by different longitudinal sections of said feed roller is delivered into different ones of said channels, said means comprising plates, one located above each channel said plates extending transversely with respect to said feed roller, the position and inclination of the plates being such as to feed material into the upper portions of the respective channels and means for adding water to said materials while flowing over said plates.

4. In a machine of the character described the combination of a plurality of separate inclined channels each having a succession of mercury retaining recesses therein, a hopper above said channels, means for directing metal bearing materials from said hopper to each of said channels to effect passage of said material over said recesses and into contact with the mercury contained therein, said means comprising at least one feed roller underlying said hopper and extending transversely of said channels and overlying a plurality of said channels so that material fed by different longitudinal sections of said feed roller is delivered into different ones of said channels, said means comprising plates one located above each channel said plates extending transversely with respect to said feed roller, the position and inclination of the plates being such as to feed material into the upper portions of the respective channels, means for adding water to said materials while flowing over said plates, and means for adjusting the inclination of said plates.

5. In a machine of the character described the combination of a series of inclined amalgamating trays arranged end to end, each tray comprising an upwardly and rearwardly extending bottom wall, an upwardly and forwardly extending lower wall, a downwardly and forwardly extending portion connected with said upwardly and forwardly extending wall and a rearwardly and downward- 1y extending portion attached to the upper end of said bottom wall, the said upwardly and forwardly extending wall being adapted to lie against said rearwardly and downwardly extending portion of the next lower tray and said forwardly and downwardly extending portion bein adapted to overlie a portion of the downwardly and forwardly extending bottom wall of the next lower tray, whereby theseveral trays are supported in overlapping relation so that material may pass over the successive trays downwardly and forwardly.

6. An amalgamating tray for a machine of the character described adapted to be arranged end to end with other trays of like construction comprising a bottom wall, a lower edge wall and two side walls extending upwardly therefrom at substantially a right angle thereto, an outwardly extending flange portion connected with said end wall and a flange portion attached to and extending downwardly from said bottom wall, the said end wall being adapted to lie against said downwardly extending flange of the next lower tray and said outwardly extending flange portion being adapted to overlie a portion of the bottom wall of the next lower tray, whereby a plurality of such trays may be connected end to end in overlapping relation and form a channel over which metal bearing material may be passed in reactive relation with amalgamating material in said several trays.

'7. In a machine of the character described the combination of means forming a channel having a succession of mercury retaining recesses therein, and means for directing metal bearing material through said channel and into contact with the mercury in said recesses, said channel being formed by a series of separately removable trays arranged end to end each formed with a pocket, mercury in said pockets and rods of amalgamable material floating on said mercury.

8. In a machine of the character described the combination of a plurality of separate inclined channels each having a succession of mercury retaining recesses therein, a hopper above said channels, and means for directing metal bearing materials from said hopper to each of said channels to efiect passage of said material over said recesses and into contact with the mercury contained therein, said means comprising at least one feed roller underlying said hopper and extending transversely of said channels and overlying a plurality of said channels so that material fed by different longitudinal sections of said feed roller is delivered into different ones of said channels, said means comprising plates, one located above each channel said plates extending transversely with respect to said feed roller, the position and inclination of the plates being such as to feed material into the upper portions of the respective channels.

EDDIE G. THOMPSON. 

